code: def likelihood(self, samples, funcs, func_params):
      ret = np.ones(CurveModel.NUM_INSTANCE)
      for i in range(CurveModel.NUM_INSTANCE):
          for j in range(1, self.step + 1):
              ret[i] *= self.normal_distribution(
                  j, samples[i], funcs, func_params
              )
      return ret
  
imports: import scipy
  import logging
  import numpy
  import time
  from scipy import optimize
label_desc: Use image node_id 8 for calling the CurveModel obj's underlying member method code with example usage: obj.likelihood(samples, funcs, func_params) and returns: ret